摘要
某地铁用锚固螺栓在使用过程中发生断裂失效。采用断口形貌检查、扫描电镜观察、化学成分分析、硬度测试及金相显微组织分析等方法,分析了螺栓的断裂性质和失效原因。结果表明,螺栓的断裂性质属于疲劳断裂。螺栓滚丝成型时,在螺纹齿根处形成了拉伤沟表面缺陷,使该处的抗疲劳性能降低,且使用过程中螺纹齿根处易产生应力集中,从而促进了疲劳裂纹的萌生及扩展,最终导致螺栓断裂失效。
Anchor bolt of a subway during using process occurred fracture failure. By fracture appearance examination, scanning electron microscope （SEM） observation, chemical composition analysis, hardness testing, metallurgical microstructure analysis and other methods, the fracture mode and failure reasons of the bolt were analyzed. The results show that the fracture mode of the bolt is fatigue fracture. With bolt thread rolling forming, the thread root place form strain groove surface defect, to reduce its anti-fatigue performance, and the thread root place during using process easy to produce stress concentration, so as to promote the fatigue crack initiation and propagation, which eventually led to the bolt fracture failure.
出处
《机械》
2013年第5期71-73,共3页
Machinery
关键词
地铁
锚固螺栓
表面缺陷
疲劳断裂
subway
anchor bolt
surface defect
fatigue fracture
